diff --git a/playground/EpoxyHello.Avalonia11/ViewModels/MainWindowViewModel.cs b/playground/EpoxyHello.Avalonia11/ViewModels/MainWindowViewModel.cs
index 7cbe7188..8504537b 100644
--- a/playground/EpoxyHello.Avalonia11/ViewModels/MainWindowViewModel.cs
+++ b/playground/EpoxyHello.Avalonia11/ViewModels/MainWindowViewModel.cs
@@ -48,6 +48,23 @@ public sealed class MainWindowViewModel
     public MainWindowViewModel()
     {
         // A handler for window opened
+        //this.MainWindowWell.Add(
+        //    //Window.WindowOpenedEvent,
+        //    "Opened",
+        //    () =>
+        //    {
+        //        this.IsEnabled = true;
+        //        return default;
+        //    },
+        //    (window, obj, ptr) => {
+        //        var dlg = new EventHandler(obj, ptr);
+        //        window.Opened += dlg;
+        //    },
+        //    (window, obj, ptr) => {
+        //        var dlg = new EventHandler(obj, ptr);
+        //        window.Opened -= dlg;
+        //    });
+
         this.MainWindowWell.Add(
             Window.WindowOpenedEvent,
             () =>
diff --git a/playground/EpoxyHello.Wpf/EpoxyHello.Wpf.csproj b/playground/EpoxyHello.Wpf/EpoxyHello.Wpf.csproj
index 8d1eade7..693119ff 100644
--- a/playground/EpoxyHello.Wpf/EpoxyHello.Wpf.csproj
+++ b/playground/EpoxyHello.Wpf/EpoxyHello.Wpf.csproj
@@ -4,8 +4,9 @@
 
   <PropertyGroup>
     <OutputType>WinExe</OutputType>
-    <TargetFrameworks>net461;netcoreapp3.1;net5.0-windows;net6.0-windows;net7.0-windows</TargetFrameworks>
+    <TargetFrameworks>net461;netcoreapp3.1;net5.0-windows;net6.0-windows;net7.0-windows;net8.0-windows</TargetFrameworks>
     <UseWPF>true</UseWPF>
+    <EpoxyBuildDebug>false</EpoxyBuildDebug>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/playground/EpoxyHello.Wpf/ViewModels/MainWindowViewModel.cs b/playground/EpoxyHello.Wpf/ViewModels/MainWindowViewModel.cs
index 3e356c54..86c52d2d 100644
--- a/playground/EpoxyHello.Wpf/ViewModels/MainWindowViewModel.cs
+++ b/playground/EpoxyHello.Wpf/ViewModels/MainWindowViewModel.cs
@@ -24,6 +24,7 @@
 using System.IO;
 using System.Linq;
 using System.Threading.Tasks;
+using System.Windows;
 using System.Windows.Controls;
 using System.Windows.Media;
 using System.Windows.Media.Imaging;
@@ -36,7 +37,7 @@ namespace EpoxyHello.Wpf.ViewModels;
 [ViewModel]
 public sealed class MainWindowViewModel
 {
-    public Command Ready { get; }
+    public Well<Window> MainWindowWell { get; } = Well.Factory.Create<Window>();
 
     public bool IsEnabled { get; set; }
 
@@ -48,12 +49,32 @@ public sealed class MainWindowViewModel
 
     public MainWindowViewModel()
     {
-        // A handler for window loaded
-        this.Ready = Command.Factory.Create(() =>
-        {
-            this.IsEnabled = true;
-            return default;
-        });
+        // A handler for window opened
+        //this.MainWindowWell.Add(
+        //    //FrameworkElement.LoadedEvent,
+        //    "Loaded",
+        //    () =>
+        //    {
+        //        this.IsEnabled = true;
+        //        return default;
+        //    },
+        //    (window, obj, ptr) => {
+        //        var dlg = new EventHandler(obj, ptr);
+        //        window.Opened += dlg;
+        //    },
+        //    (window, obj, ptr) => {
+        //        var dlg = new EventHandler(obj, ptr);
+        //        window.Opened -= dlg;
+        //    });
+
+        this.MainWindowWell.Add(
+            //FrameworkElement.LoadedEvent,
+            "Loaded",
+            () =>
+            {
+                this.IsEnabled = true;
+                return default;
+            });
 
         // A handler for fetch button
         this.Fetch = Command.Factory.Create(async () =>
diff --git a/playground/EpoxyHello.Wpf/Views/MainWindow.xaml b/playground/EpoxyHello.Wpf/Views/MainWindow.xaml
index b39a8110..e092455b 100644
--- a/playground/EpoxyHello.Wpf/Views/MainWindow.xaml
+++ b/playground/EpoxyHello.Wpf/Views/MainWindow.xaml
@@ -27,15 +27,12 @@
         xmlns:viewmodels="clr-namespace:EpoxyHello.Wpf.ViewModels"
         xmlns:converters="clr-namespace:EpoxyHello.Wpf.Views.Converters"
         mc:Ignorable="d"
-        Title="EpoxyHello.Wpf" Height="450" Width="800">
+        Title="EpoxyHello.Wpf" Height="450" Width="800"
+        epoxy:Fountain.Well="{Binding MainWindowWell}">
 
     <Window.DataContext>
         <viewmodels:MainWindowViewModel />
     </Window.DataContext>
-
-    <epoxy:EventBinder.Events>
-        <epoxy:Event EventName="Loaded" Command="{Binding Ready}" />
-    </epoxy:EventBinder.Events>
    
     <DockPanel>
         <Button DockPanel.Dock="Top"
diff --git a/src/Epoxy.Build/ViewModelInjector.cs b/src/Epoxy.Build/ViewModelInjector.cs
index dde35b5a..8305dcaf 100644
--- a/src/Epoxy.Build/ViewModelInjector.cs
+++ b/src/Epoxy.Build/ViewModelInjector.cs
@@ -60,6 +60,8 @@ public sealed class ViewModelInjector
     private readonly TypeReference propertyChangingEventHandlerType;
     private readonly TypeReference propertyChangedEventHandlerType;
 
+    private readonly TypeDefinition? wellExtensionType;
+
     private readonly MethodDefinition addPropertyChanging;
     private readonly MethodDefinition removePropertyChanging;
     private readonly MethodDefinition addPropertyChanged;
@@ -81,6 +83,9 @@ public sealed class ViewModelInjector
     private readonly MethodDefinition itAddPropertyChanged;
     private readonly MethodDefinition itRemovePropertyChanged;
 
+    private readonly MethodDefinition? wellAddMethod;
+    private readonly MethodDefinition? wellAddTEventArgsMethod;
+
     public ViewModelInjector(string[] referencesBasePath, Action<LogLevels, string> message)
     {
         this.message = message;
@@ -102,6 +107,18 @@ public ViewModelInjector(string[] referencesBasePath, Action<LogLevels, string>
             }
         );
 
+        var epoxyPath = referencesBasePath.
+            Select(basePath => Path.Combine(basePath, "Epoxy.dll")).
+            First(File.Exists);
+
+        var epoxyAssembly = AssemblyDefinition.ReadAssembly(
+            epoxyPath,
+            new ReaderParameters
+            {
+                AssemblyResolver = assemblyResolver,
+            }
+        );
+
         var fsharpEpoxyPath = referencesBasePath.
             Select(basePath => Path.Combine(basePath, "FSharp.Epoxy.dll")).
             FirstOrDefault(File.Exists);
@@ -118,6 +135,12 @@ public ViewModelInjector(string[] referencesBasePath, Action<LogLevels, string>
         this.message(
             LogLevels.Trace,
             $"Epoxy.Core.dll is loaded: Path={epoxyCorePath}");
+        if (epoxyAssembly != null)
+        {
+            this.message(
+                LogLevels.Trace,
+                $"Epoxy.dll is loaded: Path={epoxyPath}");
+        }
         if (fsharpEpoxyAssembly != null)
         {
             this.message(
@@ -150,6 +173,9 @@ public ViewModelInjector(string[] referencesBasePath, Action<LogLevels, string>
         this.propertyChangedFSharpAsyncDelegateTypeT = fsharpEpoxyAssembly?.MainModule.GetType(
             "Epoxy.Internal.PropertyChangedFSharpAsyncDelegate`1")!;
 
+        this.wellExtensionType = epoxyAssembly?.MainModule.GetType(
+            "Epoxy.WellExtension")!;
+
         this.propertyChangingEventHandlerType = internalPropertyBagType.Fields.
             First(f => f.Name == "propertyChanging").FieldType;
         this.propertyChangedEventHandlerType = internalPropertyBagType.Fields.
@@ -196,6 +222,11 @@ public ViewModelInjector(string[] referencesBasePath, Action<LogLevels, string>
             First().AddMethod;
         this.itRemovePropertyChanged = itPropertyChangedType.Events.
             First().RemoveMethod;
+
+        this.wellAddMethod = this.wellExtensionType?.Methods.
+            First(m => m.IsStatic && m.GenericParameters.Count == 1 && m.Name == "Add" && m.Parameters.Count == 5);
+        this.wellAddTEventArgsMethod = this.wellExtensionType?.Methods.
+            First(m => m.IsStatic && m.GenericParameters.Count == 2 && m.Name == "Add" && m.Parameters.Count == 5);
     }
 
     private void InjectPropertyChangeEvents(
@@ -715,6 +746,104 @@ private static void ReplaceFieldToAccessor(
         }
     }
 
+    private static void ForEach<T>(
+        IEnumerable<T> enumerable,
+        Action<T> action)
+    {
+        foreach (var item in enumerable)
+        {
+            action(item);
+        }
+    }
+
+    private static bool ReplaceAddWell(
+        ModuleDefinition module)
+    {
+        var updatingActions = new Queue<Stack<Action>>();
+
+        // Enabled parallel processing with delayed updating
+        // when processes all CIL body streams.
+        //Parallel.ForEach(
+        ForEach(
+            module.GetTypes().
+            Where(td => td.IsClass),
+            td =>
+            {
+                foreach (var md in td.Methods.
+                    Where(md => !md.IsAbstract && md.HasBody))
+                {
+                    // (Have to make reverse order)
+                    var actions = new Stack<Action>();
+
+                    var instructions = md.Body.Instructions;
+                    for (var index = 0; index < instructions.Count; index++)
+                    {
+                        // public static void Add<TEventArgs>(this Well well, string eventName, Func<TEventArgs, ValueTask> action)
+                        // public static void Add(this Well well, string eventName, Func<ValueTask> action)
+                        var inst = instructions[index];
+                        if (inst.OpCode == OpCodes.Call &&
+                            inst.Operand is MethodReference tmr &&
+                            !tmr.HasThis &&
+                            tmr.DeclaringType.FullName == "Epoxy.WellExtension" &&
+                            tmr.Name == "Add" &&
+                            tmr.Parameters.Count == 3 &&
+                            tmr.Parameters[0].ParameterType.FullName == "Epoxy.Well" &&
+                            tmr.Parameters[1].ParameterType.FullName == "System.String" &&
+                            tmr.Parameters[2].ParameterType.Name.StartsWith("Func"))
+                        {
+                            // Makes delayed processing for application.
+                            var capturedIndex = index;
+                            actions.Push(() =>
+                            {
+                                var tmd = tmr.Resolve();
+                                if (tmd.IsPublic && tmd.IsStatic &&
+                                    tmd.CustomAttributes.Any(ca => ca.AttributeType.FullName == "System.Runtime.CompilerServices.ExtensionAttribute"))
+                                {
+                                    switch (tmd.GenericParameters.Count)
+                                    {
+                                        case 0:
+                                        case 1:
+                                            //md.Body.Instructions.Insert(capturedIndex++,
+                                            //    Instruction.Create(OpCodes.Call,
+                                            //        module.ImportReference(accessor.Getter)));
+                                            break;
+                                    }
+                                }
+                            });
+                        }
+                    }
+
+                    if (actions.Count >= 1)
+                    {
+                        lock (updatingActions)
+                        {
+                            updatingActions.Enqueue(actions);
+                        }
+                    }
+                }
+            });
+
+        if (updatingActions.Count >= 1)
+        {
+            // Updates sequentially (on this thread).
+            do
+            {
+                var actions = updatingActions.Dequeue();
+                while (actions.Count >= 1)
+                {
+                    var action = actions.Pop();
+                    action();
+                }
+            }
+            while (updatingActions.Count >= 1);
+            return true;
+        }
+        else
+        {
+            return false;
+        }
+    }
+
     public bool Inject(string targetAssemblyPath, string? injectedAssemblyPath = null)
     {
         this.assemblyResolver.AddSearchDirectory(
@@ -749,11 +878,10 @@ public bool Inject(string targetAssemblyPath, string? injectedAssemblyPath = nul
                      !td.Interfaces.Any(ii => ii.InterfaceType.FullName == this.iViewModelImplementerType.FullName)).
                 ToArray();
 
+            var injected = false;
+            var removedAccessor = new Dictionary<FieldDefinition, AccessorInformation>();
             if (targetTypes.Length >= 1)
             {
-                var injected = false;
-                var removedAccessor = new Dictionary<FieldDefinition, AccessorInformation>();
-
                 foreach (var targetType in targetTypes)
                 {
                     if (this.InjectIntoType(targetAssembly.MainModule, targetType, out var rfs))
@@ -776,23 +904,28 @@ public bool Inject(string targetAssemblyPath, string? injectedAssemblyPath = nul
                             $"InjectProperties: Ignored a type: Assembly={targetAssemblyName}, Type={targetType.FullName}");
                     }
                 }
+            }
 
-                if (injected)
-                {
-                    var module = targetAssembly.MainModule;
-                    ReplaceFieldToAccessor(module, removedAccessor);
+            var module = targetAssembly.MainModule;
+            if (ReplaceAddWell(module))
+            {
+                injected = true;
+            }
+
+            if (injected)
+            {
+                ReplaceFieldToAccessor(module, removedAccessor);
 
-                    injectedAssemblyPath = injectedAssemblyPath ?? targetAssemblyPath;
+                injectedAssemblyPath = injectedAssemblyPath ?? targetAssemblyPath;
 
-                    targetAssembly.Write(
-                        injectedAssemblyPath,
-                        new WriterParameters
-                        {
-                            WriteSymbols = true,
-                            DeterministicMvid = true,
-                        });
-                    return true;
-                }
+                targetAssembly.Write(
+                    injectedAssemblyPath,
+                    new WriterParameters
+                    {
+                        WriteSymbols = true,
+                        DeterministicMvid = true,
+                    });
+                return true;
             }
         }